Right heart catheterisation remains the definitive test for pulmonary hypertension, but most patients encounter echocardiography first, and a new real-world audit suggests the current echo algorithms are letting a substantial share of cases slip through. In a single-centre study of 549 patients referred for first-time assessment of suspected pulmonary hypertension at the Royal United Hospital in Bath, UK, researchers found that 79 percent had catheterisation-confirmed disease, with an average mean pulmonary artery pressure of 41 mmHg. Yet when the European Society of Cardiology’s transthoracic echocardiography probability algorithm was applied, nearly half of the patients it labelled as low probability turned out to have pulmonary hypertension on catheterisation.
The study, published in Echo Research & Practice, tested how the existing European and American echocardiography guidelines performed against catheterisation results, and whether adding right ventricular free wall strain, a speckle-tracking measure of the heart’s right-sided pumping chamber, would improve detection. The answer was a qualified yes: incorporating this strain measure raised the sensitivity of the European algorithm from 83 percent to 92 percent while specificity barely moved, falling from 65 percent to 62 percent. For the American Society of Echocardiography criteria, adding strain pushed sensitivity from 89 percent to 96 percent, but specificity dropped sharply from 49 percent to 36 percent.
Pulmonary hypertension is defined haemodynamically as a mean pulmonary artery pressure above 20 mmHg measured at right heart catheterisation at rest. It arises from a variety of underlying pathologies and, untreated, can be life limiting, progressing to right heart failure and often death. Early symptoms are frequently overlooked, and previous work cited by the authors indicates an average delay of two to four years between initial presentation and diagnosis, a lag that negatively affects survival in a disease where timely treatment can significantly improve life expectancy. Because of this, the accuracy of the first-line imaging test matters a great deal.
The cohort consisted of consecutive patients referred between 2014 and 2023 who had complete catheterisation data and echocardiographic images of sufficient quality for assessment under both the 2022 European and 2025 American guidelines. The group was predominantly female, at 62 percent, with a mean age of 64 years. The mean interval between the initial echo and the corresponding catheterisation was 44 days, though with a wide standard deviation of 61 days, a gap the authors partly attribute to Covid-19 lockdown disruptions to UK services in 2020 and 2021.
The European algorithm sorts patients into low, intermediate, or high echocardiographic probability of pulmonary hypertension using tricuspid regurgitation velocity together with supporting signs grouped around the ventricles, the pulmonary artery, and the right atrium and inferior vena cava. In this cohort, 51 percent of patients fell into the high probability category, 24 percent intermediate, and 25 percent low. Higher echo probability tracked with worse catheterisation haemodynamics: 96 percent of the high probability group and 77 percent of the intermediate group had catheterisation-confirmed disease, with mean pressures of 45 and 31 mmHg respectively. But in the low probability group, 44 percent, or 60 patients, still had catheterisation-confirmed pulmonary hypertension, and their mean pressure was only 23 mmHg, below the previous diagnostic threshold of 25 mmHg.
Right ventricular free wall strain quantifies longitudinal deformation of the free wall of the right ventricle by tracking the changing distances between acoustic speckles in the heart muscle through the cardiac cycle, expressed as a percentage. It is reduced in people with pulmonary hypertension compared with control groups and may carry prognostic information, but it had not previously been evaluated within the current international guideline frameworks for early detection. In this study, strain was measurable in 390 patients, 71 percent of the cohort, with a mean value of minus 18 percent. Receiver operating characteristic analysis identified minus 23 percent as the optimal cut-off, yielding a sensitivity of 80 percent and specificity of 60 percent across the whole cohort.
When abnormal strain was added to the ventricular column of the European supporting signs, false negatives fell from 14 patients to 8, a 43 percent reduction, at the cost of two false positives among patients upgraded from low to intermediate probability. Within the low probability group specifically, detection improved dramatically, with sensitivity and specificity moving from 44 percent and 56 percent to 81 percent and 63 percent. Notably, reduced strain appeared more frequently in the low probability group than any other established echo marker, and this group had the lowest catheterisation pressures, leading the authors to suggest that strain may deteriorate before other geometric and functional abnormalities of advancing disease become apparent.
The analysis also examined the newer, sex-specific strain thresholds recently proposed in a joint statement from the American Society of Echocardiography and the European Association of Cardiovascular Imaging, which set abnormal values at minus 20 percent in males and minus 21 percent in females. Applying these to the European algorithm raised sensitivity further, to 93 percent, but lowered specificity to 60 percent. Within the low probability group, the male cut-off gave a sensitivity of 50 percent with a markedly higher specificity of 88 percent, while the female cut-off produced 40 percent sensitivity and 93 percent specificity, a trade-off that shifted the balance away from catching mild disease.
The audit of the American Society of Echocardiography’s 2025 guidance, which relies on tricuspid regurgitation velocity plus at least two adjunctive signs, produced a sensitivity of 89 percent and specificity of 49 percent. The study also underscored the limits of estimating pressure non-invasively. Although echo-derived pulmonary artery systolic pressure correlated reasonably well with catheterisation values, with a correlation coefficient of 0.745, Bland-Altman analysis revealed moderate bias of 7 mmHg and wide limits of agreement ranging from minus 29 to plus 44 mmHg, meaning individual estimates could be off by amounts far too large for diagnostic use. Echo estimates of right atrial pressure fared worse still, correlating at only 0.39 with catheterisation and underestimating mean pressure by 4 mmHg on average.
Among patients in whom no tricuspid regurgitation could be measured, 14 percent of the cohort, 64 percent nevertheless had catheterisation-confirmed pulmonary hypertension, and among those with an echo-derived systolic pressure below 35 mmHg, 23 percent had the disease. Combining an elevated tricuspid regurgitation velocity above 2.8 metres per second, or an estimated systolic pressure above 35 mmHg, with at least two abnormal supporting parameters including strain yielded sensitivities and specificities of 74 and 79 percent, and 73 and 87 percent, respectively. The authors caution that this was a retrospective, single-centre study of patients referred on strong clinical suspicion, so the findings apply to populations in which pulmonary hypertension is already suspected and need prospective, multicentre validation, ideally with a screening population where false positive rates can be properly assessed. Within that scope, their conclusion is that current echo algorithms lack sensitivity for milder haemodynamic forms of pulmonary hypertension, and that adding right ventricular free wall strain may reduce missed diagnoses and help expedite low-probability patients with mildly elevated pressures toward formal diagnosis and treatment.
Subject of Research: Real-world evaluation of echocardiography guidelines and right ventricular free wall strain for detecting pulmonary hypertension
Article Title: The impact of right ventricular free wall strain on current international echocardiography guidelines for the assessment of pulmonary hypertension
Article References: Wild, C. J. B., Coghlan, G., Charalampopoulos, A., Hameed, A., Suntharalingam, J., Ross, R. M., Knight, D., Willis, J., Page, J., Gurung, A., Johnson, M., Karia, N., Oxborough, D., Peacock, O., Thompson, D., & Augustine, D. X. (2026). The impact of right ventricular free wall strain on current international echocardiography guidelines for the assessment of pulmonary hypertension. Echo Research & Practice, 13(1), Article 17. https://doi.org/10.1186/s44156-026-00114-6
Image Credits: AI Generated
DOI: 10.1186/s44156-026-00114-6
Keywords: pulmonary hypertension, echocardiography, right ventricular free wall strain, right heart catheterisation, ESC guidelines, ASE guidelines, tricuspid regurgitation velocity, sensitivity and specificity, transthoracic echocardiography, mean pulmonary artery pressure, impact, right
News Source: Ophelia Keating. (October 30, 2026). Adding Heart Strain Measurements to Echo Guidelines Catches Missed Pulmonary Hypertension. Scienmag.
